Internal-combustion engine



Oct. 30,- 1945. F. M. ASPIN 2,387,973

INTERNAL-COMBUSTION ENGINE Filed Sept. 15, 1945 Fig.7.

/- VENTOR.

Patented Oct. 3.0, 1945 2,387,913 INTERNAL-COMBUSTION nNGnvr:

Frank Metcali Asian, Bury, England Application September 15, 1943, SerialNo. 502,450 r In Great Britain June 25, 1,942

Claims. (c1. 123-48) designed for an optimum compression ratio, so

that, with a full charge under normal workin conditions, the maximum power will be obtainable. The power obtainable from the explosion or each charge is, however, dependent on many factors of design in which compression ratio and detonation control are probably predominant, it being recognized that thermal efliciency increases with increase of compression ratio, provided thatdetonation control can be maintained. The practical determining factor of compression ratio with any given fuel is therefore mainly detonation control.

.Intemal combustion engines operate most of their time at less than full throttle and therefore seldom at maximum efllciency, because control of the engine power by the usual convenient method of throttling the supply of combustible gases immediately reduces the actual compression which obtains when the charge is ignited and this immediately reduces very substantially the thermal eihclency. For example, in the case of a small car, it is computed that it requires H. P. to propel it at 60 M. P. 1-1., but only 5 H. P. to propel it at 20 M. P. H. It should follow, therefore, that for a journey of 60 miles at the slower speed the engine should require to provide only 15 H. P. hours or half that required at the higher speed and therefore that the fuel consumption should be halved. In actual fact, the fuel consumption at the different speeds will show very little difference, which indicates that the thermal efllcienoy at the slower speeds has been nearly halved, due to the lowering of the compression at which the charge is ignited, compared wlth the compression at the higher speeds.

The object oi the present invention is an improved construction of engine having means for varying the volume of the compression space, and for efiecting such variation proportionally with the volume of the explosive charge.

, The invention is particularly applicable to the construction forming the subject of my co-pendin; applications for Patent Nos. 487,613 and 02.149.

p In the accompanyin drawing:

UNITED STATES PATENT" i OFFICE,

Fig. 1 is a longitudinal section illustrating one example of the invention l L Figs 2 and 3 are diagrams showing modul cations of the invention. Fig. 4 is a detail view of a modification. As shown in the drawing, the engine has an extension 10a of the cylinder ill and ayplugslike unit ll therein embodying the cylinder head and valve H with tapered complementary gas scab ing and bearing surfaces. and an oflsetcombos tion space 12' in the valve. The plug-like unit is. axially movable in the end of the cylinder and has gas sealing rings l3 above and below its port It whilst, as can be seen, the complementary Q ports, such as IS in the cylinder extension, are flared so as to provide free passage in whichever position the plug may be located. Ontheend of the cylinder extension is a thrustplate" [6 so. cured by screws Hi and below which is rotatably mounted on part I I of a face cam. The loser part l8 or the race cam is secured toa flange on the plug H. The plug H, carries antidriction bearings 19 for the driving pinionzll. The plus 4: is restrained from rotation by a locating pin Any suitable means may be provided for rotating the cam 11. V For example, as shown in Fig. 2 the axial movement and/or mean location of the plug-like unit II is controlled by a piston 22 in a vacuum cylinder 23, together providing a pneumatic actuating mechanism,the pressure in which cylinder varies with the pre sure in the induction system of the engine, to the induction pipe 15a of which system one end of the cylinder is connected by a pipe 23a, return movement: be.- ing provided for example by a spring 231) and the action controlled by any suitable damping med-n5 such as a valve'23c.

Thus, as the pressure in the induction srstan varies as a function of both the engine speed and throttle opening. so the plug-like unit II will be moved to decrease or increase the volume of the compression space as some function of thevolume of the charge, so that the optimum, or an approximation to the optimum compression ratio. will be obtained at all times. and for all-conditions of use, especially for the lower, or throttlcd, ellg'ine power output. Instead oi controlling the movement of the plug-like cylinder head unit by variation of 'pressure in the induction system, it may be con trolled by variation of pressure in the cylinder, itself or mechanically as a function of the throttle position only or of both the engine speed and throttle position in such 'lattercase using; for

ing that the cam I1 is secured by screws l1 to' the plate [6 and that such plate hasarcuate slots r, I6 to permit rotational adjustment relative to In a multi-cylinder en-- the securing screw I6.

gine, where automatic adjustment is provided, the cams IT for each cylinder may be connected 1 7 together for synchronized movement using any means including complementary and relatively v rotatable face-cams for moving the plug-like unit itself."

2; An internal combustion engine having a cylinder; a plug-like unit axially movable at the combustion end of the cylinder for varying the volume of the combustion space whilst the engine" is 'runnin'g'and in which engine the volume of the combustiblecharge supplied to such combustion spaceis variable, and means for moving the saidplug-like unit axially to vary the volume of the said combustion space proportionally with thevolume of the said charge, said meansineluding complementary and relatively rotatable face-cams for moving the plug-like unit itself, throttle mechanism for varying the volume of the combustible charge supplied to the engine and coupling means connecting said throttle mechanism to a rotatable face cam.

3'. internal combustion engine having a cylinderpa' plug-like unit axially movable at the combustion end of'the cylinder, a rotary valve .member mounted in the said plug-like unit,

means i forfpreventing rotation of the plug-like unit,, an oiT- set combustionspace in the rotary valve member, complementary ports in the pluglike unit and in the cylinder, gas sealing rings in the plug-like unit located aboveand below-such ports,'ia-nd.means for moving-the said plug-like unit axially for determining-the volume of the combustion space'in the cylinder at the end of the plug-like unit. a a. l nn -internal combustionjengine having 'a cams. a

cylinder, a plug-like unit axially movable at the combustion end of the cylinder, a rotary valve member mounted in the said plug-like unit, means for preventing rotation of the plug-like unit, an off-set combustion space in the rotary valve member, complementary ports in the pluglike unit and in the cylinder and means for moving the said plug-like unit axially for varying the, volume of the combustion space-in the cylinder at "theend 'f the said plug-like unit, whilst the engine is running, said means comprising complementary and relatively rotatable face 6. An' internal combustion engine having a cylinder, a plug-like unit axially movable at the com bustion endpr the cylinder, a rotary valve member lmou'nted' "in the said plug-like unit, means for preventing rotation of the plug-like unit, an "off-set combustion space in the rotary valve member, complementary ports in the pluglike unit and in the cylinder and means for 'moving the said plug-like unit"axiallyg-'for varying the volume of the combustion space proportion;- ally with the volume ofcombustible charge supply to the engine, said means comprisingco plementary and relatively rotatable face cam's for'moving' ,the plug-like ,unit', throttle mechanism for varying thvolumeof' the combustible supply to the engine and coupling means connecting said throttle mechanism to a rotatable facecam. 1.

7; An internal combustion engine having a cylinder, a plug-like unit axially movable at the combustion end of; the cylinder, a rotary :valve member mounted in the said plug-like unit, means for preventing rotation of the plug-like unit, an off set combustion space in the rotary valve member, complementary ports in the pluglike unit and'inthe cylinder and means f ormow ing the said plug-like unit axially for varying the volume of the combustion space in Ithecylinder at the end of thesaid plug-like unit, whilst the engine is running, said means comprising complementary, and; "relatively, rotatable face cams in combinationfwith gas sealing rings in the plug-like unit located above and below the said 'complementaryvports. r

8. An, internal combustion engine, having a cylinder, a plug-like unit axially. movable at the plementary and relatively rotatable face cams for moving the plug-like unit, throttle'mechanism for. varying the volume of the combustible supply-to the engine and coupling means connecting .said throttle mechanism to a rotatable face cam in combination with gas sealingrings inthe plug-like unitlocated above; and? below the said complementaryports. 1

9. An internal combustion "engine "havin g a cylinder; a plug-like unit axially 'mova'ble at th combustion end of the cylinder for varying the volume of the combustion space, 'saidi' plug-like unit having a portf'a rotaryvali' e mounted': in the plug-like unit and provided with a port cornplementary to the port meetin -1m unitfand means for eflecting axial movement of the pluglike unit when the valve is rotated.

10. An internal combustion engine having a cylinder, a plug-like unit axially movable at the combustion end of the cylinder for varying the 6 volume of the combustion space, said plug-like unit having a port, a rotary valve mounted in the plug-like unit and provided with a port comrotated.

FRANK ASPIN. 

